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| Titel |
Palaeo plant diversity in subtropical Africa – ecological assessment of a conceptual model of climate–vegetation interaction |
| VerfasserIn |
V. P. Groner, M. Claussen, C. Reick |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 10 ; Nr. 11, no. 10 (2015-10-14), S.1361-1374 |
| Datensatznummer |
250117436
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| Publikation (Nr.) |
 copernicus.org/cp-11-1361-2015.pdf |
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| Zusammenfassung |
We critically reassess a conceptual model here, dealing with the potential
effect of plant diversity on climate–vegetation feedback, and we provide an
improved version adjusted to plant types that prevailed during the African
Humid Period (AHP). Our work contributes to the understanding of the timing
and abruptness of vegetation decline at the end of the AHP, investigated by
various working groups during the past 2 decades using a wide range of
model and palaeo-proxy reconstruction approaches. While some studies indicated
an abrupt collapse of vegetation at the end of the AHP, others suggested
a gradual decline. Claussen et al. (2013) introduced a new aspect in the
discussion, proposing that plant diversity in terms of moisture requirements
could affect the strength of climate–vegetation feedback. In a conceptual
model study, the authors illustrated that high plant diversity could
stabilize an ecosystem, whereas a reduction in plant diversity might allow
for an abrupt regime shift under gradually changing environmental conditions.
In the light of recently published pollen data and the current state of
ecological literature, the conceptual model by Claussen et al. (2013)
reproduces the main features of different plant types interacting together
with climate, but it does not capture the reconstructed diversity of AHP
vegetation. Especially tropical gallery forest taxa, indirectly linked to
local precipitation, are not appropriately represented.
With a new model version adjusted to AHP vegetation, we can simulate a diverse
mosaic-like environment as reconstructed from pollen, and we observe a
stabilizing effect of high functional diversity on vegetation cover and
precipitation. Sensitivity studies with different combinations of plant types
highlight the importance of plant composition on system stability, and the
stabilizing or destabilizing potential a single plant type may inherit.
The model's simplicity limits its application; however, it provides a useful
tool to study the roles of real plant types in an ecosystem and their
combined climate–vegetation feedback under changing precipitation regimes. |
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